Intrinsically narrowband pair photon generation in microstructured fibres

TL;DR

This paper demonstrates the generation of intrinsically narrowband photon pairs in birefringent photonic crystal fibers, achieving high interference visibility and entanglement fidelity without spectral filtering, advancing quantum communication technologies.

Contribution

It introduces a method to produce narrowband photon pairs directly in PCFs, improving quantum interference and entanglement quality without additional filtering.

Findings

Unfiltered Hong-Ou-Mandel interference of 77% within the same PCF

Interference visibility of 80% between separate sources

Modeling results align with experimental photon purities

Abstract

In this paper we study the tailoring of photon spectral properties generated by four-wave mixing in a birefringent photonic crystal fibre (PCF). The aim is to produce intrinsically narrow-band photons and hence to achieve high non-classical interference visibility and generate high fidelity entanglement without any requirement for spectral filtering, leading to high effective detection efficiencies. We show unfiltered Hong-Ou-Mandel interference visibilities of 77% between photons from the same PCF, and 80% between separate sources. We compare results from modelling the PCF to these experiments and analyse photon purities.